In recent years, as one of countermeasures with respect to an environmental problem, a hybrid vehicle, a fuel cell vehicle, an electric vehicle, and the like running with a drive force of a motor attract attention. In such vehicles, electric equipment such as a motor, a generator, an inverter, a converter, and a battery generate heat due to supply and reception of power. Therefore, these electric equipment need to be cooled.
Japanese Patent Laying-Open No. 2000-73763 (PTD 1) discloses a cooling device for a hybrid vehicle. The cooling device includes a first cooling circuit for cooling an engine cylinder head and a driving motor selectively or concurrently, a second cooling circuit for cooling an engine cylinder block, and a third cooling circuit for cooling a power electric control unit for performing a drive control to the driving motor.
According to the cooling device disclosed in Japanese Patent Laying-Open No. 2000-73763 (PTD 1), a system for circulating cooling water is used between a heat-generating body and a radiator is used to cool electric parts, like a usual vehicle cooling only an engine. Such a system needs a radiator for cooling electric parts to be newly provided, causing a problem of low vehicle-mountability.
In view of the above, there has been proposed a technology of cooling a heat generating body by utilizing a vapor compression refrigeration cycle used as a vehicle air-conditioning device. For example, Japanese Patent Laying-Open No. 2007-69733 (PTD 2) discloses a system for cooling a heat generating body utilizing a cooling agent for an air conditioning device. In the system, a heat exchanger for performing a heat exchange with air for air-conditioning and a heat exchanger for performing a heat exchange with a heat-generating body are arranged in parallel on a cooling agent passage extending from an expansion valve to a compressor.
Japanese Patent Laying-Open No. 2005-90862 (PTD 3) discloses a cooling system. In the cooling system, heat-generating body cooling means for cooling a heat-generating body is provided on a bypass passage bypassing a decompressor, an evaporator, and a compressor of a refrigeration cycle for air-conditioning. Japanese Patent Laying-Open No, 2001-309506 (PTD 4) discloses a cooling system. In the cooling system, a cooling agent of a vehicle air-conditioning refrigeration cycle device is circulated to a cooling member of an inverter circuit portion for performing a drive control to a vehicle running motor to suppress cooling of air-conditioning air flow by an evaporator of a vehicle air-conditioning refrigeration cycle device when cooling of the air-conditioning air flow is not necessary.
On the other hand, various technologies for cooling a charger mounted on a vehicle have been proposed conventionally. For example, Japanese Patent Laying-Open No. 4-275492 (PTD 5) discloses a cooling device. According to the disclosure, a charger for rectifying power supplied from a power source to charge a battery is provided in an electric vehicle, and a cooling liquid circulating path is piped so as to go through the charger, and a cooling liquid pump circulates cooling liquid present in the cooling liquid circulating path. Japanese Patent Laying-Open No. 7-312805 (PTD 6) discloses a device, in which both ends of a circulating pipe for circulating cooling fluid are connected to a main body casing of a vehicle-mounted charger, and an electric pump motor for circulating the cooling fluid in the circulating pipe is provided, and a radiator for cooling the cooling fluid is also provided.